Double-walled tube for heating and cooling purposes



Apr. 24 1923.

E. WIIIT N flN DOUBLE WALLED TUBE FOR HEATING AND COOLING PURPOSES FilmMarch 4', 191.3

all"

it'll tit] tilt

ttll

tilt

Patented Apr, 24, 1923 l WTUEZFNMANN, 0F FFUFXHETFT, GER/MAW.

lDUWllEllLllih-W'MLFFD TURF! FtJlEt HEATING AND tltltlllilllll'fitFURFUSEF.

hpplication tiled March 4t, 19W.

serial No. $203M.

(@lltdlt'l'liltl unnnn THE rnovrarons FF THE ht'lll Hit" ltltllltflld 3,1953]., ll FTAT. In, 1313.)

This invention relates to a double-walled tube which is intended forheating and cooling purposes and is provided with undulated walls, theundulations running spirally around the tube like the threads of a screwand forming a spirally-shaped channel encompassing the inner space ofthe tube and serving to receive the heating or cooling medium, such as aliquid, a gas, air, or the like.

"Owing to this configuration oi the heating or cooling tube, theexchange of the heat is very efficacious and the tube is renderedyieldable and pliable so that no special means for compensation andelongation is required.

in order to make my invention more clear, ll refer to the accompanyingdrawings, in which:

Figure 1 shows a piece of a heating or cooling tube constructedaccording to my invention, the piece of tube being represented partly inside-view and partly in longitudinal section;

Figures 2, 3, t, 5 and 6 show portions of similarly shaped tube walls insection, the difl'erences being explained in the detailed part of thisspecification.

Referring to Figure l, the double tube consists of two tubes ofapproximately screw-threadlilre appearance, one of the tubes enclosingthe other, both having undulations torming continuous convolutions orthe metal bands 0: b, and the undulations or eonvolutions of the twotubes being ditterently shaped in sectionso as to form be tweenthemselves a spirally-shaped channel 0 through which the heating orcooling medium, i. e., an appropriate liquid, gas, air, or the like, isled. c is the space within the tube 5, through which the medium to beheated is conducted. The neighbouring rims or edges (5 of the metalbands a and b are tightly connected or united with each otlher bysoldering, welding, folding, or the li (e,

in the form of construction shown in Fig ure 2, the sectional shapes ofthe undulated metal bands are not different, but practically one likethe other, each band forming two groove-like depressions and betweenthese latter a ledge-like elevation. The rims at may be connected eitherby soldering or by electric or autogenous welding.

The form of execution shown in Figure 3 resembles that just described,there being solely the difference that the rims oi the metal bands arecovered by an appropriately profiled band 6. instead of employing aspecial band, such as 6, one of the rims of the outer tube band may beadequately bent round so as to form a fold for connecting the two tubebands with each other as in Figure at.

The section of the metal hands a Z) may be also that of a ll, as shownin Figure 5, the legs oi the Us having diflerent length so as thereby toform the channel 0 The edges oi the legs are again connected with eachother by soldering, welding, folding, or in any other manner. Two ormore of such or similar ti -shaped grooves or depressions, in connectionwith an elevation or with elevations between them, may be provided inone metal band of appropriate breadth as shown in Figure 6.

Having now described my invention, what ll claim as new and desire tosecure by a patent of the United States is:

1. A double-walled tube comprising an inner wall consisting ct onecontinuous spiral strip, an outer wall consisting of one con tinuousspiral strip having its oonvolutions extending in the same direction tothat ot the strip of the inner wall, the opposite edges of said stripsbeing bent outwardly and the outwardly bent edges of said strips beingconnected together.

2. A tube of the character described com. prising an inner and outerwall, said walls each consisting of a corrugated strip oi lltltl metaland the opposite edges of said corthe strips together whereby a spiralchannel rugated strips being connected together. will be formed.

3. A tube of the character described com- In testimony whereof I afiixmy signature prising an inner and outer wall, each of said in presenceof two witnemes.

5 walls consisting of a corrugated spiral strip EMIL WITZENMANN.

of metal, the corrugations of each strip ex- Witnesses: tending parallelwith the edges thereof and MAso ALT, means for connecting the adjacentedges of FRANZ BINNINGER.

